Boom! NASA to Demolish Spacecraft in the Name of Science

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Work is underway to create a spacecraft that won't be rocketed
into outer space but will be purposely destroyed on the ground.

DebriSat is a 110-pound (50 kilograms) satellite that's a double
for a modern low-Earth orbit spacecraft in terms of its
components, materials used, and fabrication procedures. But once
fabricated and tested, DebriSat is doomed.

Those appraisals deal with debris as small as 1 millimeter for
critical space assets and for good orbital debris environment
definition, Liou said. Some of the distributions for "large"
fragments can be obtained from the U.S. Space Surveillance
Network (SSN) observations. But the SSN data are limited to
10-centimeter (4 inches) and larger objects. "Laboratory-based
experiments are necessary to collect data for smaller debris," he
said.

As a modern satellite target, obliterating DebriSat is expected
to improve the NASA standard satellite breakup model.

Laboratory-based impact tests

Liou pointed out that the Department of Defense (DoD) and NASA
have conducted quite a few laboratory-based impact tests in the
past. One of the key experiments supporting the development of
the NASA and DoD satellite breakup models was called SOCIT, short
for Satellite Orbital debris Characterization Impact Test series.

In one SOCIT ground experiment in 1992, the target was a
flight-ready U.S. Navy Transit satellite built in the 1960s. But
that was then, and this is now. Present day satellites
incorporate many different technologies and materials than
spacecraft designed over 40 years ago.

"As new materials and new construction techniques are developed
for modern satellites, there is a need to conduct additional
laboratory-based tests and use the new data to further enhance
the breakup models," Liou said.

Integrity of the destructive outcome

A University of Florida team is designing and fabricating
DebriSat for its eventual demise.

To put DebriSat together, a wide-ranging study was done of past
low-Earth orbit satellite designs and missions within the last 15
years for spacecraft ranging from one kilogram to 5,000 kilograms
(2.2 pounds to 11,023 pounds).

This study identified modern trends in hardware, material, and
construction practices utilized in recent LEO missions. While
DebriSat is an engineering model, specific attention is being
placed on the quality, type, and quantity of the materials used
in its fabrication to ensure the integrity of the destructive
outcome.

With the exception of software, all other aspects of the
satellite's design, fabrication, and assembly integration and
testing will be as rigorous as that of an actual flight vehicle,
according to officials involved in the DebriSat effort.

DebriSat is now slated to undergo a hypervelocity impact test in
early 2014, said Norman Fitz-Coy, associate professor in the
Department of Mechanical and Aerospace Engineering and director
of the Space Systems Group at the University of Florida, which is
in Gainesville. He is leading the university's DebriSat team.

A hypervelocity impact test is one in which the amount of energy
experienced during a
typical impact between two orbiting satellites is replicated,
Fitz-Coy told SPACE.com. The test will be performed at the Air
Force's Arnold Engineering Development Center in Tennessee.

Once busted up, how much work is involved in piecing together
just how the satellite reacted to the impact?

"We are not actually gluing the satellite back together,"
Fitz-Coy said. "Rather we are characterizing — size, shape, etc.
— of the fragments resulting from the impact. This is a labor
intensive exercise."

NASA's Liou said that after the hypervelocity test, the
University of Florida experts will collect fragments down to
roughly 0.08 inches (2 millimeters) in size. That's about as long
as a nickel is thick.

The dimensions of the resulting fragments will then be measured
individually. That data will be delivered to NASA and the Air
Force Space and Missile Systems Center.

The NASA Orbital Debris
Program Office will lead the effort to analyze the data and use
the information to enhance the satellite breakup model, Liou
said.

Leonard David has been reporting on the space industry for
more than five decades. He is a winner of last year's National
Space Club Press Award and a past editor-in-chief of the National
Space Society's Ad Astra and Space World magazines. He has
written for SPACE.com since 1999.